The present invention relates to holders for burnable coils. More particularly, it relates to holders that minimize the tendency of such coils to be snuffed out during use.
Mosquito coils and other burnable coils such as incense coils are designed to burn slowly. As a result, they are somewhat susceptible to being snuffed out if they are positioned on a flat surface when they are burning. This is because such a surface can draw too much heat from the coil, slowing or even extinguishing combustion.
A variety of holders have therefore been designed to support such coils during burning. One provides a single vertical central post to support the coil. The coil is impaled on the post so that it is elevated entirely up off of whatever surface the post projects upwardly from. Because the coil is only supported at a single point by such a post and that point is the last part of the coil to be burned, the coil is usually able to burn until it reaches its end.
However, such coils are often made of materials that readily absorb humidity from the air. In highly humid conditions (such as those conditions in which mosquito coils may well be most valuable), the coils can sag when supported only from the center. This can lead to breakage or to the outside of the coil's touching a supporting flat surface, thereby snuffing the coil.
Another approach to supporting burning coils is to position the coil on a metal Wire screen. See eg. U.S. Pat. No. 3,796,002. The disclosure of this patent (and of all other publications referred to herein) are incorporated by reference as if fully set forth herein. However, such screens are typically metallic and therefore good heat conductors. This can itself lead to too much heat loss from the coil which, together with the fact that a coil on a wire screen support is in contact with the screen at numerous positions, can increase the chance of the coil's being snuffed.
U.S. Pat. No. 4,126,958 uses glass fiber nets to support a mosquito coil. While the heat loss to the screen is reduced as compared to metallic screens, the coil is still in continuous contact with the net at numerous points. Also, these nets had to be clamped to a lid and body.
In U.S. Pat. No. 4,765,090 a coil is formed with integral, downwardly projecting bumps that act as integral legs to hold the coil up off of a supporting surface. However, this significantly complicates the manufacturing process for the coils.
Yet another approach is to provide a metal can whose lower base has positioned thereon an array of upwardly turned metal tabs. This approach requires the coil to rest on numerous tabs simultaneously.
It can therefore be seen that a need exists for an improved burnable coil holder.